Classes were canceled Thursday at a southwest Houston synagogue after bomb threats.
The threats were made to Congregation Beth Israel and Congregation Or Ami. Both synagogues received threats by voicemail Tuesday night.
The Department of Homeland Security, Houston police department, the Anti-Defamation League, and the FBI are on alert.
Beth Israel's day school, The Shlenker School, was closed so police bomb-sniffing dogs could sweep the building, according to a statement from Ricki Komiss, head of The Shlenker School.
The news of the phoned in bomb threat caught families who live in the area off guard.
"It grabbed my attention it was so strange, I couldn't believe. When I saw the picture of the synagoge I was sure it was just my area," said Bella Osnova.
The school is expected to reopen on Friday and extra security personnel will be on campus, according to Komiss.
Congregation Or Ami does not have a day school.